Vinyl pyridines are known from the literature to react with amines to form the corresponding 2-animoethylpyridine derivatives. Doering and Weil, JACS, 1947, 69, 2461 describe the reaction of 2-vinylpyridine with diethylamine at high temperature to give low yields of .alpha.-diethylamino-.beta.-(2-pyridyl)-ethane, and a similar reaction of 2-vinylpyridine with piperidine to yield N-.beta.-(2-pyridyl)-ethylpiperidine. Magnus and Levine, JACS, 1956, 78, 4127, describe the reaction of 4-vinylpyridine and 2-methyl-5-vinyl-pyridine with various primary and secondary amines to form the corresponding pyridylethylated products and recommends the use of acetic acid or hydrogen chloride as condensing agent with secondary amines and the use of sodium metal as condensing agent when pyrrole is used as the amine. Phillips, JACS, 1956, 78, 4441 describes the preparation of various 4-(substituted aminoethyl)-pyridines by the addition of secondary and primary amines to 4-vinylpyridine, and suggests acid catalysis of the reaction. Chemical Abstracts, 51, 5074a describes condensation of 4-vinyl-pyridine and 2-methyl-6-vinylpyridine with 1-4 moles primary and secondary alkyl and aryl amines using acetic acid as catalyst.
German Pat. No. 2359107 describes the formation of 2-methylaminoethyl-pyridine, useful in treating circulatory diseases, from 2-vinylpyridine by reaction with MeNH.sub.2 AcOH or MeNH.sub.2 EtCO.sub.2 H. Swiss Pat. No. 387993 describes the preparation of pharmaceutically-active N-substituted aminoethyl pyridines by reacting 2-(or 4-) vinyl alkyl pyridines with amines in the presence of Co.sup.++ or Cu.sup.++ with polyfunctional anion-exchangers. Swiss Pat. No. 367094 describes the pyridylethylation of N-containing heterocycles with vinylpyridines at elevated temperatures in an organic solvent containing a base, and reports treating heterocycles such as pyrrole, indole or carbazole with .beta.-vinylpyridine in dimethylsulphoxide. U.S. Pat. No. 3,410,861 discloses the preparation of pharmaceutically-active .beta.-(2- or 4-pyridyl alkyl)-amines by reaction of a lower alkyl primary amine addition salt with vinylpyridine in aqueous medium. There is no disclosure in this prior art of the use of the 2-aminoethyl-pyridine derivatives having corrosion inhibiting properties.
Various amines are known as a corrosion inhibitor. U.S. Pat. No. 3,976,593 describes lower monoalkyl, preferably C.sub.1 and C.sub.2 2-substituted pyridines such as 2-ethylpyridine as examples of corrosion inhibiting amines.